taciturnity

taciturn +‎ -ity, from Latin taciturnitas.

taciturnity (countable and uncountable, plural taciturnities)

1. The trait of being taciturn.
   • 1835, William Gilmore Simms, The Partisan, Harper, Chapter VI, page 69:

     Humphries broke out more freely into speech than he had done before, for his usual characteristic was that of taciturnity.

   • 2021, Adam Liptak, Justice Clarence Thomas, Long Silent, Has Turned Talkative, in: The New York Times, May 3 2021

     Once he is back on the bench, will Justice Thomas revert to his usual taciturnity?

2. (law, Scotland) Failure to assert a legal right in a way that implies that it is being given up.